The present disclosure generally relates to display panels in head-mounted displays (HMDs), and specifically to correcting non-uniformity errors in such display panels.
HMDs may be used to present augmented and/or virtual information to a user. For example, a virtual reality (VR) headset can be used to simulate virtual environments. During a manufacturing process of the HMDs, there may be some non-uniformity that exists across any individual display panel as well as across panels of the HMDs. HMDs may use two display panels to present information to the user with each display panel presenting information to each eye. In order to create a stereoscopic image, images displayed on the left and right panels are fused together (overlaid) to create a perception of depth. It is desirable that the corresponding points between the two display panels have the same color and brightness. If non-uniformity exists between the brightness (or luminance) of corresponding pairs of pixels or between color matching of corresponding pairs of sub-pixels of the left and right display panels, the user's eyes may not be able to fuse the images together properly, causing eye strain on the user. Any such non-uniformity is corrected by applying non-uniformity calibration data while a host system renders content for display on the HMDs.
The non-uniformity in display panels becomes more or less noticeable as its luminance level varies, such that panels displaying content at lower luminance levels have more noticeable non-uniformity relative to when displaying content at higher luminance levels. Conventionally, non-uniformity calibration is applied at a reference luminance level for content irrespective of a luminance level of the content being displayed on the HMD, reducing user experience.